The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions
We investigate the mean locally measured velocity dispersions of ionized gas (σ gas ) and stars (σ ∗ ) for 1090 galaxies with stellar masses log (M * /M ⊙ ) ≥9.5 from the SAMI Galaxy Survey. For star-forming galaxies, σ ∗ tends to be larger than σgas, suggesting that stars are in general dynamically...
Published in: | Monthly Notices of the Royal Astronomical Society |
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Main Authors: | , , , , , , , , , , , , , , , , , , , |
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2022
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Online Access: | https://researchers.mq.edu.au/en/publications/89fa7ef7-859b-40cf-ade9-11fb2440cb2a https://doi.org/10.1093/mnras/stac509 https://research-management.mq.edu.au/ws/files/200627324/198583800.pdf http://www.scopus.com/inward/record.url?scp=85127737268&partnerID=8YFLogxK http://purl.org/au-research/grants/arc/FT140100255 http://purl.org/au-research/grants/arc/CE170100013 |
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/89fa7ef7-859b-40cf-ade9-11fb2440cb2a 2024-06-23T07:56:32+00:00 The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions Oh, Sree Colless, Matthew D'eugenio, Francesco Croom, Scott M. Cortese, Luca Groves, Brent Kewley, Lisa J. van de Sande, Jesse Zovaro, Henry Varidel, Mathew R. Barsanti, Stefania Bland-Hawthorn, Joss Brough, Sarah Bryant, Julia J. Casura, Sarah Lawrence, Jon S. Lorente, Nuria P. F. Medling, Anne M. Owers, Matt S. Yi, Sukyoung K. 2022-05 application/pdf https://researchers.mq.edu.au/en/publications/89fa7ef7-859b-40cf-ade9-11fb2440cb2a https://doi.org/10.1093/mnras/stac509 https://research-management.mq.edu.au/ws/files/200627324/198583800.pdf http://www.scopus.com/inward/record.url?scp=85127737268&partnerID=8YFLogxK http://purl.org/au-research/grants/arc/FT140100255 http://purl.org/au-research/grants/arc/CE170100013 eng eng info:eu-repo/semantics/openAccess Oh , S , Colless , M , D'eugenio , F , Croom , S M , Cortese , L , Groves , B , Kewley , L J , van de Sande , J , Zovaro , H , Varidel , M R , Barsanti , S , Bland-Hawthorn , J , Brough , S , Bryant , J J , Casura , S , Lawrence , J S , Lorente , N P F , Medling , A M , Owers , M S & Yi , S K 2022 , ' The SAMI Galaxy Survey : the difference between ionized gas and stellar velocity dispersions ' , Monthly Notices of the Royal Astronomical Society , vol. 512 , no. 2 , pp. 1765-1780 . https://doi.org/10.1093/mnras/stac509 galaxies: active galaxies: evolution galaxies: fundamental parameters galaxies: kinematics and dynamics galaxies: stellar content galaxies: structure article 2022 ftmacquarieunicr https://doi.org/10.1093/mnras/stac509 2024-06-12T23:47:25Z We investigate the mean locally measured velocity dispersions of ionized gas (σ gas ) and stars (σ ∗ ) for 1090 galaxies with stellar masses log (M * /M ⊙ ) ≥9.5 from the SAMI Galaxy Survey. For star-forming galaxies, σ ∗ tends to be larger than σgas, suggesting that stars are in general dynamically hotter than the ionized gas (asymmetric drift). The difference between σ gas and σ ∗ (Δσ) correlates with various galaxy properties. We establish that the strongest correlation of Δσ is with beam smearing, which inflates σ gas more than σ ∗ , introducing a dependence of Δσ on both the effective radius relative to the point spread function and velocity gradients. The second strongest correlation is with the contribution of active galactic nuclei (AGN) (or evolved stars) to the ionized gas emission, implying that the gas velocity dispersion is strongly affected by the power source. In contrast, using the velocity dispersion measured from integrated spectra (σ ap ) results in less correlation between the aperture-based Δσ (Δσ ap ) and the power source. This suggests that the AGN (or old stars) dynamically heat the gas without causing significant deviations from dynamical equilibrium. Although the variation of Δσ ap is much smaller than that of Δσ, a correlation between Δσ ap and gas velocity gradient is still detected, implying that there is a small bias in dynamical masses derived from stellar and ionized gas velocity dispersions. Article in Journal/Newspaper sami Macquarie University Research Portal Monthly Notices of the Royal Astronomical Society 512 2 1765 1780 |
institution |
Open Polar |
collection |
Macquarie University Research Portal |
op_collection_id |
ftmacquarieunicr |
language |
English |
topic |
galaxies: active galaxies: evolution galaxies: fundamental parameters galaxies: kinematics and dynamics galaxies: stellar content galaxies: structure |
spellingShingle |
galaxies: active galaxies: evolution galaxies: fundamental parameters galaxies: kinematics and dynamics galaxies: stellar content galaxies: structure Oh, Sree Colless, Matthew D'eugenio, Francesco Croom, Scott M. Cortese, Luca Groves, Brent Kewley, Lisa J. van de Sande, Jesse Zovaro, Henry Varidel, Mathew R. Barsanti, Stefania Bland-Hawthorn, Joss Brough, Sarah Bryant, Julia J. Casura, Sarah Lawrence, Jon S. Lorente, Nuria P. F. Medling, Anne M. Owers, Matt S. Yi, Sukyoung K. The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
topic_facet |
galaxies: active galaxies: evolution galaxies: fundamental parameters galaxies: kinematics and dynamics galaxies: stellar content galaxies: structure |
description |
We investigate the mean locally measured velocity dispersions of ionized gas (σ gas ) and stars (σ ∗ ) for 1090 galaxies with stellar masses log (M * /M ⊙ ) ≥9.5 from the SAMI Galaxy Survey. For star-forming galaxies, σ ∗ tends to be larger than σgas, suggesting that stars are in general dynamically hotter than the ionized gas (asymmetric drift). The difference between σ gas and σ ∗ (Δσ) correlates with various galaxy properties. We establish that the strongest correlation of Δσ is with beam smearing, which inflates σ gas more than σ ∗ , introducing a dependence of Δσ on both the effective radius relative to the point spread function and velocity gradients. The second strongest correlation is with the contribution of active galactic nuclei (AGN) (or evolved stars) to the ionized gas emission, implying that the gas velocity dispersion is strongly affected by the power source. In contrast, using the velocity dispersion measured from integrated spectra (σ ap ) results in less correlation between the aperture-based Δσ (Δσ ap ) and the power source. This suggests that the AGN (or old stars) dynamically heat the gas without causing significant deviations from dynamical equilibrium. Although the variation of Δσ ap is much smaller than that of Δσ, a correlation between Δσ ap and gas velocity gradient is still detected, implying that there is a small bias in dynamical masses derived from stellar and ionized gas velocity dispersions. |
format |
Article in Journal/Newspaper |
author |
Oh, Sree Colless, Matthew D'eugenio, Francesco Croom, Scott M. Cortese, Luca Groves, Brent Kewley, Lisa J. van de Sande, Jesse Zovaro, Henry Varidel, Mathew R. Barsanti, Stefania Bland-Hawthorn, Joss Brough, Sarah Bryant, Julia J. Casura, Sarah Lawrence, Jon S. Lorente, Nuria P. F. Medling, Anne M. Owers, Matt S. Yi, Sukyoung K. |
author_facet |
Oh, Sree Colless, Matthew D'eugenio, Francesco Croom, Scott M. Cortese, Luca Groves, Brent Kewley, Lisa J. van de Sande, Jesse Zovaro, Henry Varidel, Mathew R. Barsanti, Stefania Bland-Hawthorn, Joss Brough, Sarah Bryant, Julia J. Casura, Sarah Lawrence, Jon S. Lorente, Nuria P. F. Medling, Anne M. Owers, Matt S. Yi, Sukyoung K. |
author_sort |
Oh, Sree |
title |
The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
title_short |
The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
title_full |
The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
title_fullStr |
The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
title_full_unstemmed |
The SAMI Galaxy Survey:the difference between ionized gas and stellar velocity dispersions |
title_sort |
sami galaxy survey:the difference between ionized gas and stellar velocity dispersions |
publishDate |
2022 |
url |
https://researchers.mq.edu.au/en/publications/89fa7ef7-859b-40cf-ade9-11fb2440cb2a https://doi.org/10.1093/mnras/stac509 https://research-management.mq.edu.au/ws/files/200627324/198583800.pdf http://www.scopus.com/inward/record.url?scp=85127737268&partnerID=8YFLogxK http://purl.org/au-research/grants/arc/FT140100255 http://purl.org/au-research/grants/arc/CE170100013 |
genre |
sami |
genre_facet |
sami |
op_source |
Oh , S , Colless , M , D'eugenio , F , Croom , S M , Cortese , L , Groves , B , Kewley , L J , van de Sande , J , Zovaro , H , Varidel , M R , Barsanti , S , Bland-Hawthorn , J , Brough , S , Bryant , J J , Casura , S , Lawrence , J S , Lorente , N P F , Medling , A M , Owers , M S & Yi , S K 2022 , ' The SAMI Galaxy Survey : the difference between ionized gas and stellar velocity dispersions ' , Monthly Notices of the Royal Astronomical Society , vol. 512 , no. 2 , pp. 1765-1780 . https://doi.org/10.1093/mnras/stac509 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1093/mnras/stac509 |
container_title |
Monthly Notices of the Royal Astronomical Society |
container_volume |
512 |
container_issue |
2 |
container_start_page |
1765 |
op_container_end_page |
1780 |
_version_ |
1802649677111230464 |